- 1The same price for the 2 methods, compatible with ISO 14064-1 and based on the same collection and ADEME factors.
- 2The price depends on 4 variables: company size, scope 3 detail, consultancy profile, additional deliverables.
- 3Using physical data rather than spend-based ratios for scope 3 changes the bill by 30 to 60%.
- 4The 2 formats can be delivered in the same engagement, requiring a few hours of additional formatting.
- GHG Protocol or Bilan Carbone®: which costs less?
No price difference. Same work, same data.
- €11,000 to €18,000 excl. VAT for an SME using a private consultancy, €6,000 excl. VAT paid by the company with Diag Décarbon'Action.
- The 2 methods are compatible with ISO 14064-1 and use the same data and emission factors.
- The price depends on company size, the depth of scope 3 analysis and the consultancy profile.
It is often said that the GHG Protocol costs less because it involves less administration. In practice, quotations tell a different story.
1Why there is no price difference
On paper, Bilan Carbone® and GHG Protocol appear to be two competing methods. Technically, they are two reporting formats for exactly the same collection and calculation work.
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The 2 methods are compatible with each other and with the international ISO 14064-1 standard: they cover the same greenhouse gases (the 6 under the Kyoto Protocol plus NF3), distinguish direct emissions, indirect energy-related emissions and other indirect emissions, and use the same emission factor databases, primarily the ADEME Base Empreinte for French data. Data collection represents 60 to 70% of an engagement's cost, and is exactly the same regardless of the output format chosen.
What differs is the structure of the final report. Bilan Carbone® organises emissions into 11 activity categories (energy, purchasing, freight, travel, etc.). GHG Protocol organises them into 15 standardised upstream and downstream categories (purchased goods and services, upstream transport, use of sold products, end of life). Since Bilan Carbone® V9, published in July 2024 by the Association Bilan Carbone®, mapping between the two has been direct and requires only a few hours of formatting.
Requesting a GHG Protocol assessment from a consultancy that usually works with Bilan Carbone® should therefore not change your quote. If it does, ask the provider what justifies the difference.
2What makes the price vary
When 2 quotes show very different prices, the gap is explained by 4 variables independent of the method chosen.
The 4 variables that determine assessment prices
Possible variation in the final bill for an equivalent assignment
Company size and complexity. A single-site service-sector SME with 30 employees costs €8,000 to €12,000 excl. VAT. A multi-site mid-cap company with 400 employees and an international supply chain costs €25,000 to €50,000 excl. VAT. The price ratio is 1 to 5, unrelated to the method chosen: it reflects the volume of data to process and the number of contacts to involve.
The level of scope 3 detail. Scope 3 accounts for an average of 88% of a company's emissions, but can be addressed at different levels of granularity. Between scope 3 based on basic spend-based ratios and scope 3 based on physical data with precise sector emission factors, the price varies by 30 to 60%. This is the main source of differences between quotes, far more than the method chosen: the question is whether it is mandatory or not, but also, and above all, at what level.
The provider's profile. An independent ABC-certified consultancy charges €11,000 to €15,000 excl. VAT for a conventional SME engagement. A large Paris consultancy charges €25,000 to €40,000 excl. VAT for the same engagement. Self-service platforms charge less but shift much of the workload onto the internal team. The choice of provider affects the bill more than the choice of method.
Additional deliverables. An assessment alone, without an action plan or a presentation to the executive committee, costs less than a full engagement with a costed roadmap, SBTi support and a strategic presentation. Be wary of seemingly low quotes: they often exclude the action plan, the part that makes the assessment useful. We explore this in our guide to ways of reducing the cost of a Bilan Carbone®.
An example from practice: we recently audited two quotes for an SME with 80 employees. The first, labelled "GHG Protocol", asked for €28,000 excl. VAT: the consultancy billed the method as a separate deliverable, with an "international expertise" surcharge. The second, labelled "Bilan Carbone®", was €13,500 excl. VAT for exactly the same scope. The same data, ADEME factors and interviews: only the method's name on the cover justified doubling the quote. Overcharging based on this confusion still occurs, particularly for SMEs discovering the subject.
3When to choose one over the other
Since the two cost the same, the question is solely which output format makes the most sense to your contacts.
Choose Bilan Carbone® if you are a French company with a mandatory BEGES to submit on the ADEME platform, if you intend to apply for Diag Décarbon'Action (which requires the Bilan Carbone® method and an ABC-certified consultancy), if your clients are French, or if your management thinks in terms of activity categories.
Choose GHG Protocol if you publish a CSRD/ESRS E1 statement (the European climate standard for non-financial reporting) with an international perspective, if you answer a CDP investor questionnaire (Carbon Disclosure Project, a global reference for investors), if you are developing an SBTi pathway (the global framework for aligning reduction targets with the Paris Agreement), if your parent company is foreign, or if your international clients use the language of the 15 categories.
The right approach is to request both formats in the same engagement. For a competent consultancy, delivering an ADEME Bilan Carbone® report alongside a converted GHG Protocol note represents a few hours of formatting. If a provider refuses, ask why.
4The 5 points that distinguish 2 quotes
The most common mistake in tenders is comparing "GHG Protocol" and "Bilan Carbone®" quotes as if they covered different engagements. What distinguishes the proposals comes down to 5 points:
- The level of scope 3 addressed (spend-based ratios versus physical data)
- The number of consultant-days included in collection
- Whether a meaningful costed action plan is included
- The consultancy's quality: ABC certification or otherwise, senior or junior experts
- Whether a strategic presentation to the executive committee is included or only a PDF report
These are the 5 points to compare between 2 quotes.
5What to decide when two quotes arrive
When faced with 2 quotes, one "GHG Protocol" and the other "Bilan Carbone®", compare scope 3 detail, consultant-days, whether an action plan is included and the consultancy's profile: this is where the price difference lies, almost never in the method. A good provider will deliver the 2 formats in a single engagement, as the underlying work is the same.
The method is therefore chosen according to how the report will be used: French compliance, a CSRD file, an SBTi pathway, a response to a client. The budget and collection remain the same.
